This invention relates to a main contact blade assembly for a switching device, and more particularly, to a contact blade assembly for a circuit breaker wherein the configuration of the contact blade affects the arc produced between the contacts of a circuit breaker.
When the current carrying contacts of a circuit interrupting device are separated while a current is flowing through the contacts, an arc can be formed between the contacts. Depending on the intensity and duration of the arc, the contact material and materials surrounding the arc experience varying degrees of deterioration. For example, the contact surfaces can be eroded such that the resistance of the contact interface increases causing increased heating and further deterioration of the contacts. In dealing with this problem, it is desirable to either extinguish the arc in the shortest period of time possible and/or move the arc from between the contacts to a location where the damage done by the arc does not severely affect the operation of the circuit interrupting device.
Accordingly, it is important to provide means for extinguishing and/or moving an arc to a location where damage done by the arc is not critical.